视频会议软件中文档共享的实现方案及比较

Schemes and Comparisous of Documents Sharing in Video Conference System

针对由于文档格式的多样性和随机性,多点会议终端浏览文档所要求的同步性和实时性给视频会议中文档共享功能的实现带来的各种困难,提出两种文档共享功能的实现方案:IE(Internet Exp lorer)控件实现方案和屏幕截取实现方案。解决并实现了系统设计和编程过程中多种文档在同一窗口的显示、同步浏览、网络传送、图像截取和显示等难点。这两个方案已经在基于TCP/IP(Transport Control Protocol/Internet Protocol)协议的局域网和广域网上得以运用,成功地实现了多点会议终端在同一窗口环境下同步、实时地浏览多种格式的文档。通过分析比较,发现两种方案各具特色,IE控件方案编程复杂度和难度相对较小,易于实现;屏幕截取方案占用带宽少适于公网。

Aiming at lots of difficulties to the design of documents sharing when many conference terminals share the same documents, which brought by either the diversity and the randomicity of documents formats or the demands of synchronization browsing and the real-time property, two schemes of the documents sharing functions ： the IE control scheme and the screen capture scheme are presented. Difficulties such as displaying different formats of documents in a same window, browsing synchronously, sending data via Internet, capturing screen and drawing DIB picture to screen are designed and programmed. The two schemes of this paper have been used in LAN （Loral Area Network） and WAN （Wide Area Network） based on TCP/IP （Transport Control Protocol/ Internet Protocol）, and have been successfully implemented for synchronous browsing and real-time transmission for different formats of documents in a same window. Through the analyse and comparison, it has found that the two schemes both have their own characteres, there is less complex and difficult to compose the IE control scheme, so it can be iemplemented easily. But the screen capture scheme can use narrow bandwidth, and can be applied to public network.